Purge valves are in common use today for most vehicle engines. The purge valves are used to control the flow of fuel fumes from a gas tank storage canister to the engine. The charcoal canister receives vapors from the gas tank and the purge valve controls the flow of those vapors in order to reduce emissions. For example, at low engine speeds, a small amount of fumes is allowed to flow to the engine. Correspondingly, at higher engine speeds, a large amount of gas fumes is allowed to flow to the engine where they are combusted with the fuel being supplied to the engine.
Many purge valves are pulse width modulated solenoid valves. In these systems, a solenoid is operated by the electronic computerized control system for the vehicle. The solenoid in turn controls a valve which regulates the gas fume flow into the engine.
The solenoid includes an electric coil which activates a pole piece which in turn operates an armature connected to a valve member. The movement of the armature causes it to contact the pole piece, often creating a slight noise in the purge valve system. In cold temperatures when all of the parts of the purge valve are hard and stiff, the noise of the armature striking the pole piece can be significant.
It is an object of the present invention to provide an improved purge valve for a vehicle. It is another object of the present invention to provide a purge valve which has reduced noise characteristics from known purge valves.
It is a further object of the present invention to provide a purge valve in which the armature contacts the pole piece with less force and thus with less associated noise. It is a still further object of the present invention to provide a purge valve with components made of softer materials which operate to reduce the noise of the purge valve in operation.
It is also another object of the present invention to provide a purge valve which has reduced noise at lower temperatures.
These and other objects, features and benefits of the invention will become apparent from the following description of the invention when viewed in accordance with the accompanying drawings and construed in accordance with the appended claims.